Leighton Meester: The Day Before, The Day After

Leighton Meester stops by NYC’s Ed Sullivan theater on Tuesday (September 8) to tape an appearance on The Late Show with David Letterman (airing Friday). The 23-year-old Gossip Girl actress wore a Lanvin top and pants, Azzedine Alaia belt, Louboutin shoes, Bulgari jewels, and Louis Vuitton clutch.

Afterwards, Leighton attended the series premiere of The Day Before and rubbed shoulders with Proenza Schouler dynamic duo Jack McCollough and Lazaro Hernandez as well as Vogue contributing editor Lauren Santo Domingo. Leighton donned a jumpsuit and bag by Proenza Schouler and red pumps by Brian Atwood.

The Day Before is a four-part series and follows a different designer each week including Sonia Rykiel, Proenza Schouler, Karl Lagerfeld for Fendi, and Jean Paul Gaultier. It debuts TODAY (September 9) on Sundance Channel.

10+ pictures inside of Leighton Meester at The Day Before premiere…